/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.search.profile.aggregation;

import org.opensearch.common.io.stream.StreamInput;
import org.opensearch.common.io.stream.StreamOutput;
import org.opensearch.common.io.stream.Writeable;
import org.opensearch.common.xcontent.ToXContentFragment;
import org.opensearch.common.xcontent.XContentBuilder;
import org.opensearch.common.xcontent.XContentParser;
import org.opensearch.search.profile.ProfileResult;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import static org.opensearch.common.xcontent.XContentParserUtils.ensureExpectedToken;

/**
 * A container class to hold the profile results for a single shard in the request.
 * Contains a list of query profiles, a collector tree and a total rewrite tree.
 *
 * @opensearch.internal
 */
public final class AggregationProfileShardResult implements Writeable, ToXContentFragment {

    public static final String AGGREGATIONS = "aggregations";
    private final List<ProfileResult> aggProfileResults;

    public AggregationProfileShardResult(List<ProfileResult> aggProfileResults) {
        this.aggProfileResults = aggProfileResults;
    }

    /**
     * Read from a stream.
     */
    public AggregationProfileShardResult(StreamInput in) throws IOException {
        int profileSize = in.readVInt();
        aggProfileResults = new ArrayList<>(profileSize);
        for (int j = 0; j < profileSize; j++) {
            aggProfileResults.add(new ProfileResult(in));
        }
    }

    @Override
    public void writeTo(StreamOutput out) throws IOException {
        out.writeVInt(aggProfileResults.size());
        for (ProfileResult p : aggProfileResults) {
            p.writeTo(out);
        }
    }

    public List<ProfileResult> getProfileResults() {
        return Collections.unmodifiableList(aggProfileResults);
    }

    @Override
    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
        builder.startArray(AGGREGATIONS);
        for (ProfileResult p : aggProfileResults) {
            p.toXContent(builder, params);
        }
        builder.endArray();
        return builder;
    }

    public static AggregationProfileShardResult fromXContent(XContentParser parser) throws IOException {
        XContentParser.Token token = parser.currentToken();
        ensureExpectedToken(XContentParser.Token.START_ARRAY, token, parser);
        List<ProfileResult> aggProfileResults = new ArrayList<>();
        while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
            aggProfileResults.add(ProfileResult.fromXContent(parser));
        }
        return new AggregationProfileShardResult(aggProfileResults);
    }
}
